Embodiments relate to an electronic circuit and methods thereof. Some embodiments relate to a temperature independent type reference current generating device.
A reference current generator and/or a reference current source may supply a reference current that may not be influenced by power and/or temperature. A generated reference current may be radiated and/or supplied to a bias voltage of each circuit. Example FIG. 1 and FIG. 2 are diagrams illustrating circuits of a current source. Referring to FIG. 1, a current source may generate reference current IREF1 using base/emitter voltage VBE and resistance R1. A current source may generate a current, for example I1=VBE1/R1, with substantially no influence of supplied power VDD. However, VBE1 may be influenced by temperature and thus a value of reference current IREF1 generated from a current may vary according temperature.
Referring to FIG. 2, a current source may use a reference voltage with substantially no influence of temperature. A current source may generate reference current IREF2 ([Vbg−VBE1]/R′) using reference voltage Vbg, bipolar transistor Q′ and resistance R′. However, VBE1 may be influenced by temperature, and thus a temperature compensation part 5 may be provided to compensate for an influenced value. A current source may generate reference current IREF2 with no influence of power and/or temperature. However, a reference voltage source circuit generating reference voltage Vbg may be additionally provided in a current source to generate reference current IREF2. Therefore, a current source may be influenced by a temperature change and/or may require a reference voltage source circuit to generate a reference voltage.
Accordingly, there is a need of a temperature independent type reference current generating device, and a method of manufacturing a temperature independent type reference current generating device, which may be able to generate a reference current substantially without influence of a temperature and/or a supply voltage, substantially independent from a reference voltage.